1. Field
Example embodiments relate to transistors and methods of manufacturing the same, for example, insulated gate bipolar transistors (IGBTs) and methods of manufacturing the same.
2. Description of the Related Art
Insulated gate bipolar transistors (IGBTs) have a structure combining a bipolar junction transistor (BJT) and a metal-oxide-semiconductor field effect transistor (MOSFET). Thus, IGBTs have relatively good current driving characteristics from the BJT and relatively good switching characteristics from the MOSFET with an insulated gate. IGBTs may be used as devices for controlling relatively high voltage and/or relatively high current. In one example, IGBTs may be used in power devices.
A conventional IGBT includes a gate and an emitter on a front side, and a collector on a back side. In one example, the collector is a region heavily doped with impurity ions of a given, desired or predetermined conductivity-type. Another doped region is disposed adjacent to the collector. A doping profile of the back side portion of the IGBT may significantly affect operating characteristics of the IGBT, for example, hole-injection and tail current characteristics. For this reason, in order to improve operation characteristics of an IGBT, there is as demand to improve doping profiles of elements disposed on the back side portion of the IGBT.